MDS delete or not?

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AlbertaRam1500

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Ok, it’s official that a cam & lifters are going to be replaced. Shop wants to know if I’d like to delete the MDS in order to lower the risk of potential lifter failure in future. Different components + tune will be needed. Shop says it will affect my fuel economy.

My question is this…. How much fuel does the MDS system actually save? Will I notice a major decline in fuel economy? I currently get approx 650kms per tank of gas on 60/40 split of city/hwy driving. I also drive like a little old lady so I’m light on the gas. Any experiences or comments??
 

Wild one

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Ok, it’s official that a cam & lifters are going to be replaced. Shop wants to know if I’d like to delete the MDS in order to lower the risk of potential lifter failure in future. Different components + tune will be needed. Shop says it will affect my fuel economy.

My question is this…. How much fuel does the MDS system actually save? Will I notice a major decline in fuel economy? I currently get approx 650kms per tank of gas on 60/40 split of city/hwy driving. I also drive like a little old lady so I’m light on the gas. Any experiences or comments??
What shop is doing it for you?
 

Travelin Ram

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Most respondents here will lean toward deleting. Bear in mind the population here are enthusiasts and 99.99% of trucks out there the drivers never heard of MDS, don’t care.

I’m not particularly a fan myself, but I don’t hate it, and I can see the mpg bump up significantly when it’s running on 4.

AFAIK there’s no evidence that MDS operating causes lifter failure. Which is not to say Hemis don’t have issues with premature lifter failure- they certainly do.
 

Jeepwalker

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How many miles on your pickup now? Are you going to get rid of it in 3-5 years?

What are your driving patterns? If a guy was a longer distant commuter, or a lot of hwy miles, I would think it would be advantageous.
 
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AlbertaRam1500

AlbertaRam1500

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AFAIK there’s no evidence that MDS operating causes lifter failure. Which is not to say Hemis don’t have issues with premature lifter failure- they certainly do.

Hi TR…
You’re right, but from what I understand the MDS and AFM (GM) seem to suggest that premature lifter failure is generally caused by oil pressure issues. So, if I’m spending $8k (cdn) to have this job done, I’m thinking it may be in my best interest to get the delete done. The primary use of this vehicle was to tow my RV in the summer and get me out of deep snow in the winter. So, anything that may help prevent me from doing this job again in the future seems worth it.
 

Jeepwalker

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How long are you going to keep the truck?
 
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AlbertaRam1500

AlbertaRam1500

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How many miles on your pickup now? Are you going to get rid of it in 3-5 years?

What are your driving patterns? If a guy was a longer distant commuter, or a lot of hwy miles, I would think it would be advantageous.
Hi Jeepwalker.

I currently have 140,000kms on the Ram. Beautiful condition. I’m planning on keeping for at least 5 years then hoping to switch to a EV pickup.
My daily driving is slow. My commute to work is 5km and primarily use the truck to tow my 5,000lb RV. That’s when I’m on the hwy. I love the truck aside from this current repair.
 

A_mod_too_far

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Deleting mds will reduce your mpgs by 1-2
If you're not commuting a ton it's probably worth it to have a real v8 but if your spending a lot of time on the highway you may rethink that
 

jws123

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8k.. For a just a chamshaft job? Or is it a total rebuild because if its not your getting screwed over big time I do camshafts on these trucks for around 2k with parts included lol.
 
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AlbertaRam1500

AlbertaRam1500

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Thats pretty steep for
8k.. For a just a chamshaft job? Or is it a total rebuild because if its not your getting screwed over big time.

Camshaft, non MDs lifters, aftermarket manifolds, re tune alone is $1200. This also in Canadian bucks. Shop labor is $160+ per hour and labour book states it’s around 20+ hours. I also got quoted $7k for no manifolds, another shop wanted $16k for a Re/Re new motor swap. I trust this shop and I’m ok paying it.
 

Trailmaker

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MDS probably won’t engage when you are towing… I saw a difference on a vacation when I filled up 8 times. Is was a 20-25 mi difference in a 32 gallon tank. So it works a little
 

Wild one

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8k.. For a just a chamshaft job? Or is it a total rebuild because if its not your getting screwed over big time I do camshafts on these trucks for around 2k with parts included lol.
That's about par for a cam job in Canada JW,if you're having a shop do it.
 

Shawn Burns

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I previously used an Edge Pulsar tuner, which enabled you to select tunes on the fly that either allowed MDS to work or canceled it. I toggled between the two consistently, but I never really saw that much of a difference between when it was on or off.

I am now tuned by hemifever. I opted to have the MDS turned off with the tune. I do not miss it at all. I have a short commute. I am usually towing during my longer trips with my truck, so MDS wouldn't be used much anyway. Otherwise, we take my wife's SUV for family trips.

There is some anecdotal belief that the MDS can be a contributing factor to the cam/lifter failures. This is one of the reasons that I opted to have it turned off. I tried to cover all of my bases to prevent tick or cam/lifter failure.
 
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